The Antarctic ozone hole has been a subject of extensive scientific investigation since its discovery in the mid-1980s because the stratospheric ozone layer shields our planet from damaging UV light. Thus ozone depletion increases solar radiation at the surface thereby increasing the risk of damage to humans, flora and fauna (Chipperfield et al., 2015). Similarly, there is still large stratospheric polar ozone loss (15-35 km) in the colder winters in the Arctic region (Chipperfield et al., 2005). Significant progress has been made in understanding the processes controlling stratospheric ozone changes during the recent decades through measurements and model simulations (e.g. Feng et al., 2011). Recently, Hand (2016) reported that a possible record Arctic ozone hole may occur in the winter/spring 2015/16 due the extreme persistent low stratospheric temperature this year. Therefore, we will investigate the stratospheric Arctic polar ozone depletion for 2015/16 using our off-line 3-D chemical transport model (CTM) TOMCAT/SLIMCAT and satellite observations (e.g., MLS) and compare with previous winters (Feng et al., 2007). TOMCAT/SLIMCAT is a NCAS community CTM which contains a detailed description of stratospheric and tropospheric chemistry as well as a detailed aerosol module. The model has been widely used to study transport and chemistry in the upper troposphere and lower stratosphere (UTLS) (e.g., Mahieu et al., 2014; Dhomse et al., 2015; Hossanini et al., 2015) and also for WMO ozone assessment and described in detail by Chipperfield (2006, www.see.leeds.ac.uk/slimcat).

For this project, the student will learn the atmospheric transport and chemistry in the stratosphere and be trained to analyze the model output (large data sets) and satellite observations. The student will also quantify the stratospheric ozone loss for Arctic winter/spring for 2015/16 and compare with previous winters using model simulations and satellite data.